Endometriosis is a disorder characterized by the presence of histologically normal endometrial tissue outside the uterus. Endometriosis often presents with symptoms that mimic gastrointestinal disorders such as Crohn's disease, which makes it's diagnosis extremely difficult. Both disease produce similar symptoms, and their pathogenesis still remains to be elucidated. The objective of this study is to elucidate the the role of TNF/TNFR expression in rats models of intestinal endometriosis and Crohn's disease. The proposed rat model of Crohn's disease has been extensively used to study the pathophysiology of this disease. The rat model of intestinal endometriosis wil specfically address the pathopysiological role of TNF/TNFR expression in the implantation of ectopic endometrium in the intestine. The specific aims of the proposed plan are to: 1)determine the TNF'-aipha mRNA and protein expression in the implants, intestine, and peritoneal fluid in a rat model of intestinal endometriosis and compare with the rat model of Crohn's disease 2) determine the expression on TNF receptors (TNFR1/TNFR2) in the endometrial implants and associated intestine in a rat model of intestinal endometriosis and compare with the rat model of Crohn's disease 3) determine the expression of tumor necrosis factor receptor-associated factors (TRAFs) in both animals models and, 4) establish a specific pathophysiological role of TNF/TNFR signaling for the rat model of intestinal endometriosis and the rat model of Crohn's disease.